Abstract

The characteristics of an electrically injected spin polarized single photon source have been investigated. The GaAs-based microcavity diode consists of a single InAs/GaAs self-organized quantum dot as the single photon source and a Schottky tunnel barrier for the ferromagnetic contact to inject spin polarized electrons. The measured output circular polarization of the biexciton emission at exhibits a switching behavior as a function of magnetic field, in the Faraday geometry, the value remaining near-zero for and for . The linear polarization shows a complementary trend. The results are explained in the framework of the exciton fine structure in the quantum dot and the effects of electron-hole exchange splitting, due to in-plane quantum dot anisotropy, and Zeeman splitting on the spin eigenstates and their coupling to the photon field.